[portman123456789]

I Have an 07 Forman 500 and l live in south east florida (Ft. Lauderdale) and I just bought, K&N filter w/Outer wear Pre Filter,Hmf Utility Exaust, and a Dyno Jet Kit. After following dyno jet Instructions (Main Jet 170,needle on 3rd Slot down from top and air/mix screw out 2 1/2 turns)I found that at .25 to full throttle the bike was bucking and surging and did not have much power.So then i continued to raise the clip on the needle to the 2nd slot then drove.Then the 1st slot and drove again and found the bike road better but was still bucking slighty.Then I choose to change main jet to 165 and started the needle at 3rd slot down from top and continued to raise slots on needle until the bike road the best. I found that the bike road best with 165 main jet and the needle on the 2nd slot down from the top.I was Just wanting to known If that sounds o.k and if anyone In the same area as I had the same setup and could tell me a better way to set it up or if the way i am diagnosing this problem is right or wrong.
The reason for asking is that when I am going full thottle and I slightly let off the gas to .75 thottle the bike bucks real quick but feals good after that.
And I also had to turn the air mix screw out to about 3 turns to solve the backfire problem when I let off the thottle to decellerate.
Any Information will be much apprecited.Thank You.

 

[portman123456789]

I found that that problem I was having was cause by either the 1.5" spa hose I was using was to small in diameter or the way I routed the hose.It was not allowing enough air into the airbox.So I made a new snorkle using Marcust's setup.and put a 170 main jet and needle on the 3rd slot down and now the bike run's great.But I think I am going to try a 175 main jet and see how it run's.I will post the results when I try that.Thank for the post Marcust!